Frost dates · Connecticut
Connecticut frost dates,
county by county.
Last spring frost and first fall frost probability data for all 9 counties in Connecticut, computed from the NOAA 1991–2020 Climate Normals. Every county page surfaces the full probability table at three temperature thresholds plus crop-specific planting guidance.
Variation across Connecticut
25 days separate the earliest and latest counties.
The median last spring frost in Greater Bridgeport Planning Region is March 26 — 25 days earlier than Northwest Hills Planning Region at April 20. Statewide averages aren't useful planting tools; pick your county below for the data that actually applies to your fields.
By frost timing
Counties sorted by last spring frost.
Latest at top, earliest at bottom. In most states this matches the north-to-south gradient.
- Northwest Hills Planning RegionSpring Apr 20·Fall Oct 25188-day season
- Western Connecticut Planning RegionSpring Apr 18·Fall Oct 27192-day season
- Northeastern Connecticut Planning RegionSpring Apr 16·Fall Oct 28195-day season
- Lower Connecticut River Valley Planning RegionSpring Apr 10·Fall Oct 30203-day season
- Naugatuck Valley Planning RegionSpring Apr 10·Fall Oct 30203-day season
- South Central Connecticut Planning RegionSpring Apr 4·Fall Nov 6216-day season
- Capitol Planning RegionSpring Apr 3·Fall Nov 5216-day season
- Southeastern Connecticut Planning RegionSpring Apr 1·Fall Nov 5218-day season
- Greater Bridgeport Planning RegionSpring Mar 26·Fall Nov 19238-day season
Alphabetical
All Connecticut counties — A to Z.
- Capitol Planning Region
- Greater Bridgeport Planning Region
- Lower Connecticut River Valley Planning Region
- Naugatuck Valley Planning Region
- Northeastern Connecticut Planning Region
- Northwest Hills Planning Region
- South Central Connecticut Planning Region
- Southeastern Connecticut Planning Region
- Western Connecticut Planning Region